A ‘toolbox’ approach for in-building coverage?

In-building coverage is the latest industry hot-topic and seems to be getting a lot of attention, and increasingly so over recent months. As the requirement for increased coverage and capacity continues, and more people than ever are using mobile phones and tablets as opposed to landlines, the enterprise market (which some might say has been lagging behind a little up until now) is also waking up to this issue and looking at ways of solving it, with an ‘inside-out’ approach to building networks.

So what are the options?
The landscape of in-building coverage, to some, seems to have become more complex, with several options available for increasing both coverage and capacity within a given location. The choice can be somewhat confusing, so what really is best and for which scenario?

We are all familiar with the symbol synonymous with a wifi hotspot or ‘zone’ and many environments now offer free connection – great if you want to do some web-browsing or answering of emails, however, wifi is no good if you need to make a call. You still need connection to a cellular network.

So in short, wifi can act as a great overlay and complement other solutions well to support data traffic. But for a more holistic approach, there does need to be a cellular connection in there somewhere too.

As an aside, there are also some question-marks over the security and reliability of a wifi solution as it doesn’t operate over licensed frequencies – another thing to consider.

Small cells
There has been much debate for several years over what actually constitutes a ‘small cell’, with talk of femtocells, picocells and the like. Essentially a small cell is about bringing the network closer to its users. Small cells work well to fill in coverage ‘not-spots’ as well as increasing capacity where it is required – inside and outside.

However, the largest down-side to a small cell network is that it is a single-operator, single-band, single-technology solution and what the in-building environment really needs is a multi-operator, multi-band, multi-technology solution. Therefore theoretically different small cells networks have to be provided for each operator – resulting in potential interferences as well as hand-off issues as users move between cells. This is obviously not a practical solution.

Distributed antenna systems
This solution utilises a network of antennas around a space that are all connected to a central master unit, to deliver both coverage and capacity, often in places where the macro-network cannot reach. Distributed Antenna Systems (DAS) can work on multiple frequencies and can therefore provide multi-operator, multi-frequency band, multi-technology networks on the same hardware – a definite plus point. They effectively work to extend the existing external network and can often utilise the existing infrastructure already inside a building or location, such as a metro system or stadium.

Opinions differ in terms of the cost of a DAS as many feel they are an expensive alternative to some of the other solutions. However the benefit of a DAS comes in the total cost of ownership (TCO) where it can often offer savings over alternative systems in the longer term. Our DAS is future-proof (working on 2G, 3G and 4G) meaning network upgrades are less frequent and the solution is flexible and scalable, allowing for the addition of units in an efficient ‘plug and play’ manner.

Still confused???
So after looking briefly at each solution, the real answer is that there is no ‘one size fits all’ approach to the challenge of in-building coverage. A ‘toolbox’ of systems that complement each other is often what is required. Perhaps a DAS that can backhaul a wifi and small cell network for example, or an overlay installation of small cells on top of a DAS system, where the DAS provides umbrella coverage and the small cells cater for extra dense areas.

The important thing is to consider all options during the planning stage to ensure that the system you install can keep up with future industry developments as well as providing you with both the coverage and capacity you need to provide an effective network for your users…whether they’re office workers, sports fans or rail travellers.

We will shortly be running a webinar with the GSMA on ‘Intelligent networks: what is the future of in-building wireless coverage?’ so why not join us to learn more from other industry experts, including ABI Research and mobile operator EE on this exact topic?


Rami Rami Hasarchi
Director, Commercial and Special Projects, Axell Wireless

Rami Hasarchi has more than 30 years of experience in the high-tech industry, many of which in the wireless and cellular markets. Rami is the registered inventor for several patents associated with the use of digital signal processing (DSP) within coverage products.


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